A fuel distributor rail, which is mounted on an internal combustion engine via a holder, is described in U.S. Pat. No. 7,406,946 B1. A connection element of the holder is connected via a screw to the internal combustion engine. The connection element of the holder is furthermore connected to a tubular base element of the fuel rail. It is possible that the connection element of the holder is connected to the tubular base element of the fuel rail by a solder connection.
The mounting of the fuel rail on the internal combustion engine described in U.S. Pat. No. 7,406,946 B1 has the disadvantage that tension peaks arise because of notches, in particular at the transition between the connection element of the holder and the tubular base element of the fuel rail. Another disadvantage is that the individual components, especially the connection element of the holder and the tubular base element of the fuel rail, must be radially held in place during the joining process in order to achieve the desired position on the joined component. This is especially critical for permanently connected components, such as components joined by a solder connection, where the gap between the individual components, in particular the tubular base element and the joined element, must be minimal.
Furthermore, it is necessary to produce a geometry at the component(s) to be attached, in particular the connection element, that is nearly identical to the tube geometry of the tubular base element of the fuel rail, which is an involved process. This becomes even more difficult as the enclosure angle of the component(s) to be attached becomes smaller. For example, this may require a detection of the particular diameter segment with the aid of measuring technology and a comparison with the required drawing information.
Another disadvantage may result with regard to a pre-joining process. Especially in a pre-joining process that is carried out in the form of tacking, especially by welding, for the positioning prior to a subsequent soldering process for the final connection, the welding connection frequently breaks before the final fixation, which consequently results in scrapped pieces. In addition, tacking points may weaken the tubular base element and the attachment part(s).
If the attachment part(s) is/are developed as formed parts, they typically exhibit residual stresses due to the high degree of reforming. These residual stresses may also be unleashed by subsequent manufacturing processes, such as a heat treatment during the soldering process, which has a considerable adverse effect on the dimensional accuracy of the finished components.
Because of the specifications, in particular the connection to the tubular base element, the space and the connection geometry, as well as the contour resulting therefrom, the typically reformed attachment parts furthermore have geometrically disadvantageous regions, such as notches, which lead to stress characteristics that feature stress peaks.
Furthermore, the typically radial connection requires a large solder surface since it is stressed with regard to pealing. This results in poor controllability of the soldering process. In addition, the risk of flaws in the soldering surface grows as the contact area becomes larger. A lot of solder is required for large soldering surfaces, which is also disadvantageous from the financial standpoint.
Moreover, long bent parts are typically flexible in at least one loading direction. This results in low natural frequencies and high stressing.